Businesses are increasingly using service providers to host critical applications and data in order to better control the security and availability of the data and to mitigate the expenses associated with hosting and serving data locally to the entire business user base. They access these applications and data over the service provider’s business edge network. This creates a challenge for the service provider, because their customers measure the success of the network by its ability to handle critical data and provide a superior user experience. With more and more applications and data centralized, the importance of the network, and its role in the success of the business, becomes ever more critical.
If you are considering how best to do Layer 2 stretch for virtual machine mobility, then you might be considering Overlay Transport Virtualization (OTV). OTV designed by Cisco to offer L2 stretch with what they said was an easy to deploy protocol. It was only available on the Nexus switching product line, which didn’t support VPLS/MPLS. Until recently MPLS/VPLS was Juniper’s recommended technology for network segmentation and Layer 2 stretch, which Cisco also offers on the ASR routers. We’ve recently announced E-VPN, which is MPLS/VPLS based and brings all of the benefits of VPLS and then some. Cisco has announced E-VPN on the ASR router as well. Now that E-VPN is available, maybe it’s time to consider your best option. Let’s take a look at why OTV isn’t the best choice for VM mobility and why E-VPN is.
Organizations are increasingly using virtual machine mobility to optimize server resources, ensure application performance and to aid in disaster avoidance. Typically VM live migration has relied on increasing the scale of the L2 broadcast domain to ensure that the VMs can be reached after migrations using their current addressing. This has resulted in the increasing use of VLANs and the need for L2 extension over the WAN. As a result organizations are looking for ways overcome the limitations with VLAN scale and for methods to extend the L2 domain over the WAN that ensure the best performance. VxLAN has emerged as an alternative technology to VLANs, and EVPN has emerged at a better way to transport VMs over the WAN. Together these technologies can enable VM live migration over the WAN, or long distance Motion in VMware parlance, but they need to all work together effectively and this is where OVSDB, VxLAN routing and a new technology from Juniper called ORE come in to play.
Organizations need to insure that their applications are available and performing. Server virtualization helps by enabling virtual machine mobility. If a server is overworked or will be unavailable vMotion can be used to migrate live workloads to another server in the current data center or in another data center. This requires that the addressing including the MAC, IP address and VLAN ID remain the same so that sessions are not dropped when the VM move happens. This is done by extending the L2 domain to the new location, know as Layer 2 stretch. Within a subnet this is easy to do. Across subnets in the data center it becomes more difficult. Doing live migration over the WAN introduces considerable challenges. Juniper has introduced a number of technologies to make virtual machine live migration possible.
In conversations with customers across the Asia Pacific, one recurrent topic has been the constant uphill battle they face in managing the complexity of their IT environment with limited IT resources. As their organisations grow, the traditional approach to connecting more users and servers and rolling out more applications, has been to deploy more ports and switches. This has inevitably led to a proliferation of interconnected devices resulting in more devices to manage and troubleshoot.
As we look back on the last couple of weeks there was a lot of news about networking that we are still taking in. The networking industry is evolving and there are important considerations to make as you build out your networks. We are seeing an ever increasing need for bandwidth, a need for greater application awareness and the need to quickly provision, trouble shoot and adapt the network to ensure application performance and availability. As a result we are seeing a transition to software defined networks. If you are building networks to serve your business then you are probably considering how your choices today will affect your ability to respond to the changes that come in the future. How do you get to where you need to be? What is best for your organization?